Researchers at William & Mary's Virginia Institute
of Marine Science (VIMS) have created an interactive map that allows web users
to see the coverage of underwater grasses in the Chesapeake Bay and its
tributaries.

The tool, created using Google Maps® by researchers
in the Submerged Aquatic Vegetation (SAV) program at VIMS, is designed to help
resource managers, scientists and citizens better track and visualize bay-grass
restoration

Underwater grasses serve many essential functions in
the Chesapeake Bay and other coastal ecosystems. Grasses give critical shelter
to young striped bass, blue crabs and other key species; improve water clarity;
add oxygen to the water; reduce shoreline erosion; and provide food for
over-wintering waterfowl.

Each year, scientists with the SAV program at VIMS
conduct an aerial survey and collaborate with colleagues in Virginia and
Maryland in field studies of underwater grass coverage in the Bay. This
information is used to gauge progress towards the Chesapeake Bay Program's goal
of restoring underwater grasses to 185,000 acres in the Bay and its tidal
tributaries by 2010.

Professor Robert "JJ" Orth, head of the SAV program at
VIMS, says "We've always been interested in providing users with timely access
to maps and data for current and past annual surveys. We moved our monitoring
reports, maps, and data to our web site early on, but were never fully
satisfied with the access speed."

Orth says access to the new map is much faster. In
addition, the map displays charts showing the coverage of underwater grasses in
particular areas from 1970 until present.

"As you zoom in, the map switches from an overall Bay
chart, to zone charts, and finally to individual segment charts," says Orth.
"Zoom in even further, and the green areas denoting SAV coverage resolve into
different colors that denote the density of underwater grasses in each bed."
These density data, painstakingl

y interpreted from aerial photography by
program scientists, tell the user whether the grass coverage in a particular
bed is sparse, moderately thick or very thick.

Users can also select what to display on the map,
showing or hiding the colored bed areas, choosing between Google Maps'
"satellite view" with aerial imagery or "map view" with roads and location
names. Users can also choose to show or hide the historical charts and the
boundaries of the geographic segments used to report bay-grass coverage.

The map was created using Google Maps and ESRI ArcGIS®
Server by David Wilcox, a geographic information systems analyst in the SAV
program at VIMS. In the future, Orth and Wilcox expect to add additional data
layers including SAV aerial imagery, historical bed areas and field
observations, along with other enhancements.

Launched in 2005, Google Maps is a free web-mapping
service application that powers many map-based services on the web. Google
estimates that users spend one million hours a day using it and its sister
product, Google Earth.